Welcome to the forums Chris
Congrats on the sprog
Yes, unfortinately your rad is now probably knackered. The thermochill rads come with a bag of screws, and these are still too long if you dont use the neoprene gasket, so it's always best to be careful.
I believe that over-clock.co.uk will do a repair on the rad for about a tenner, but youll have to pay the postage both ways, which wont be cheap because of the weight. Might be worth emailing them to check, but if you have punctured it with 12 screws, the chances are that it is knackered anyway.
You can always try soldering it yourself and then leaktesting
Let the graphics card dry out in a warm place for a while, it might fix itself.
